Iron builds up within stars, particularly in the Red Giants, during its formation, the red giant converts all of its helium into carbon and oxygen atoms.
These atoms eventually combine to form iron, the heaviest atom that can form a star.
When most of these atoms are converted into iron, a supernova occurs.
A supernova explosion in space, scattering iron, oxygen, and carbon throughout the galaxy.
The exploded fragments are pulled together by gravity to form planets.
Earth's core is made up almost entirely of metals, especially iron and nickel.
